here's dennis murphy. >> for most of us who enjoy spending time in the water and an occasional swim, a dunk in a back yard pool will suffice. but for the more adventurous, only total submersion in the open ocean will do. a ticket to paradise. >> it's a majestic world. it's just awe inspiring. >> it's incredibly peaceful. you're down there with the fish. you look around you and it's amazing wonder. the closer you look, the more beautiful it gets. >> all of your senses are getting overloaded. the visual colors are phenomenal. >> david swain and his wife shelley tyre shared that passion for scuba diving. >> get me in the water, that's where i belong. >> so to escape a winter in '99 they got on a sailboat. if a carefree vacation is what you want, it doesn't get much better than this. >> was shelley looking forward to it? >> yeah. it was a different experience for her. sbl she was a big fish person. >> yeah. anything with critters. that was what she was about. >> she liked to count fish under water. he liked to photograph. what could go wrong? turns out a lot. they were around tortola whe